4. Definition:
• Loudspeaker (or "speaker") is an electro‐acoustic transducer
that produces sound in response to an electrical audio signal
input.
• Loudspeakers may be divided into two main groups: ‐ cone type
and horn type
5. History:
Alexander Graham Bell
In 1876, Alexander Graham Bell (inventor of the
telephone) patented the first idea of the
loudspeaker. The loudspeaker is written either
loudspeaker, loud-speaker, or speaker and it did
not use electricity. He made the loudspeaker as an
intelligible speech as part of the telephone.
6. Basic Design:
• Basic Design Components A loudspeaker works on the basis that
like charges repel and opposite charges attract and when current
flows through a conductor, a magnetic field is produced around it.
There are two important components in a speaker that cause
movement:
• Basic Design The Voice Coil and Magnet Voice Coil MagnetCore
• Basic Design Components The voice coil and a magnet. The voice
coil is a long winding piece of copper than is rapped around a
circular drum called a core. The voice coil is suspended above the
centre of a large magnet with the end of the voice coil attached to
10. Dynamic Loudspeaker:
• The most common type of driver, commonly called a
dynamic loudspeaker.
• It has a light weight diaphragm, or cone, connected to a
rigid basket, or frame, via a flexible suspension, commonly
called a spider, that constrains a coil of fine tensile wire to
move axially through a cylindrical magnetic gap.
• When an electrical signal is applied to the voice coil, a
magnetic field is created by the electric current in the voice
coil, making it a variable electromagnet.
11. Cont...
• The coil and the driver's magnetic system interact, generating a
mechanical force that causes the coil (and thus, the attached cone)
to move back and forth, thereby reproducing sound under the control of
the applied electrical signal coming from the amplifier.
12. Cabinet Loud Speaker:
• The cabinet improves the acoustic response of the
cone type speakers.
• The basic design consists of an enclosure with the
loudspeaker unit set in the centre of a large box,
which is completely air tight except for a port and
the loudspeaker hole in the front panel.
• The port is so proportioned to the interior volume
of the enclosure and to the loudspeaker
characteristics that it functions acoustically as a
low frequency loudspeaker.
13. Line Source or Column Speaker:
• Column Speakers use multiple speaker
cones create a slim line column offering
excellent vertical sound dispersion with a
long 'throw', but limited horizontal
coverage.
• For this reason, several column speakers
can be mounted in a cluster and are often
used around pillars for sound
reinforcement.
14. High Fidelity (Hi‐Fi) Speaker:
• These are used to reproduce the generally
audible frequency range of 50 Hz to 12 KHz
(out of the entire audio range of 20 Hz to 20
KHz).
• The frequency response of ordinary
speakers is irregular, with a number of
resonant peaks and valleys, and has a range
of about 60 Hz to 8 KHz only.
15. What are woofers?
• Woofer is designed to produce low frequency
sounds, typically from around 40 hertz up to
about a kilohertz or higher.
• The most common design for a woofer is the
electro dynamic driver, which typically uses a
stiff paper cone, driven by a voice coil which is
surrounded by a magnetic field.
• The voice coil is attached by adhesives to the
back of the speaker cone.
• The voice coil and magnet form a linear electric
motor.
16. Cont...
• When current flows through the voice coil, the coil moves in
relation to the frame according to Fleming's left hand rule,
causing the coil to push or pull on the driver cone in a
piston‐like way.
• The resulting motion of the cone creates sound waves as it
moves in and out.
17. Tweeter:
• A tweeter is a loudspeaker designed to
produce high audio frequencies, typically
from around 2,000 Hz to 20,000 Hz
(generally considered to be the upper limit
of human hearing).
• Specialty tweeters can deliver high
frequencies up to 100 kHz.
18. Horn Loud Speaker:
• A horn loudspeaker is a loudspeaker or
loudspeaker element which uses a horn to
increase the overall efficiency of the driving
element, typically a diaphragm driven by an
electromagnet.
• The horn itself is a passive component and
does not amplify the sound from the driving
element as such, but rather improves the
coupling efficiency between the speaker
driver and the air.
